Any way to set/add tags on a file with Applescript under Mavericks?

Trying to move some of my scripts over from labels to tags under Mavericks, but I can't seem to find a way to set/add tags with Applescript.

Anybody that know how to do this? As far as I can figure tags aren't actually new, just new in terms of being a more central part of the updated Finder.

You can use xattr. This copies the tags from file1 to file2:

xattr -wx com.apple.metadata:_kMDItemUserTags "$(xattr -px com.apple.metadata:_kMDItemUserTags file1)" file2
xattr -wx com.apple.FinderInfo "$(xattr -px com.apple.FinderInfo file1)" file2

The tags are stored in a property list as a single array of strings:

$ xattr -p com.apple.metadata:_kMDItemUserTags file3|xxd -r -p|plutil -convert xml1 - -o -
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
    <string>Red
6</string>
    <string>aa</string>
    <string>Orange
7</string>
    <string>Yellow
5</string>
    <string>Green
2</string>
    <string>Blue
4</string>
    <string>Purple
3</string>
    <string>Gray
1</string>
</array>
</plist>

The tags for colors have values like Red\n6 (where \n is a linefeed).

If the kColor flag in com.apple.FinderInfo is unset, Finder doesn't show the circles for colors next to files. If the kColor flag is set to orange and the file has the red tag, Finder shows both red and orange circles. You can set the kColor flag with AppleScript:

do shell script "xattr -w com.apple.metadata:_kMDItemUserTags '(\"Red\\n6\",\"new tag\")' ~/desktop/file4"
tell application "Finder" to set label index of file "file4" of desktop to item 1 of {2, 1, 3, 6, 4, 5, 7}

'("Red\n6","new tag")' is old-style plist syntax for this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
    <string>Red
6</string>
    <string>new tag</string>
</array>
</plist>

xattr -p com.apple.FinderInfo file|head -n1|cut -c28-29 prints the value of the bits used for the kColor flag. Red is C, orange is E, yellow is A, green is 4, blue is 8, magenta is 6, and gray is 2. (The flag that would add 1 to the values is not used in OS X.)

The answer has been posted on the Applescript user list:

http://lists.apple.com/archives/applescript-users/2015/Jan/msg00193.html

quote from page- code written by Shane Stanley

You can do it easily enough with AppleScriptObjC. Here's are handlers to retrieve tags, set tags, and add tags:

use scripting additions
use framework "Foundation"

on returnTagsFor:posixPath -- get the tags
    set aURL to current application's |NSURL|'s fileURLWithPath:posixPath -- make URL
    set {theResult, theTags} to aURL's getResourceValue:(reference) forKey:(current application's NSURLTagNamesKey) |error|:(missing value)
    if theTags = missing value then return {} -- because when there are none, it returns missing value
    return theTags as list
end returnTagsFor:

on setTags:tagList forPath:posixPath -- set the tags, replacing any existing tags
    set aURL to current application's |NSURL|'s fileURLWithPath:posixPath -- make URL
    aURL's setResourceValue:tagList forKey:(current application's NSURLTagNamesKey) |error|:(missing value)
end setTags:forPath:

on addTags:tagList forPath:posixPath -- add to existing tags
    set aURL to current application's |NSURL|'s fileURLWithPath:posixPath -- make URL
    -- get existing tags
    set {theResult, theTags} to aURL's getResourceValue:(reference) forKey:(current application's NSURLTagNamesKey) |error|:(missing value)
    if theTags ≠ missing value then -- add new tags
        set tagList to (theTags as list) & tagList
        set tagList to (current application's NSOrderedSet's orderedSetWithArray:tagList)'s allObjects() -- delete any duplicates
    end if
    aURL's setResourceValue:tagList forKey:(current application's NSURLTagNamesKey) |error|:(missing value)
end addTags:forPath:

If you save it them in a script library, you can also use them from Mavericks.

-- Shane Stanley www.macosxautomation.com/applescript/apps/